Revision #552 → #1234 · back to history
addedFour color theorem3693f64a0465
addedFive color theorem565c09587423
addedGraph-theoretic formulation (chromatic number)8e31ec509c05
addedAdjacency of regions8401c2453bc6
addedSame-country map requiring five colors1f8f3e88ffeb
addedMap represented as planar graph154b1d020cda
addedEvery planar graph is four-colorable684397c690df
addedDe Morgan's four-areas postulate4f0a2fa1dafe
addedHeawood: five color theorem and genus generalizationa3c0d6105b89
addedTait's snark equivalence45ebe9b6b8ab
addedHadwiger conjecturee10646c12fc5
addedMinimal counterexample requiring five colorse9e782bcb6e4
addedUnavoidable set83ef95300b7f
addedReducible configuration09d002361a1f
addedQuadratic-time 4-coloring algorithm67cda6f6cbc8
addedSnark conjecture proof41667ef16663
addedReduction to triangulated graphs8374aafd09be
addedEdge-face count relation 2e = 3f82fb71d8cf46
addedDegree of a vertexaeb94c99b6c5
addedExistence of a vertex of degree 5 or less0259cd60e960
addedExistence of minimal 5-chromatic graph932dd01f99b6
addedNo vertex of degree 3 or less in minimal graph676da71e51c3
addedNo vertex of degree 4 in minimal graph0a951dd4ef11
addedKempe chain160d1f952786
addedConfigurationdf2ac608cef4
addedReducible configuration (general)e563452d9e4f
addedUnavoidable set (general)ff64ed6f1351
addedRing and k-ring configuration0db13a4ede53
addedInitially good coloring19926b7ec86b
addedMethod of dischargingece91408397d
addedImmersion reducibility108aa4465e93
addedColor restriction is not transitive344a42c9ea4a
addedNP-completeness of three-coloring planar maps4ab87911450f
addedThree-coloring of cubic mapsf9de09682665
addedMissouri and Nevada neighbor parity29e3a366ab07
addedFour color theorem for infinite planar graphsd4a37ca0a9f2
addedDe Bruijn–Erdős theorem11e0995fb8dc
addedColors needed depend on Euler characteristica89618b725ca
addedOrientable surface formula in terms of genus3f20e63da20a
addedHeawood conjecture12878d38fd00
addedKlein bottle requires only six colorse3e5829b1c62
addedTorus requires seven colors96310aab19bd
addedMöbius strip and 1-planar graphs require six colorsa28363b76585
addedReal projective plane requires six colorsfd1181aade2a
addedEarth–Moon problem chromatic bounds0d0719008e31
addedFolded rods needing arbitrarily many colorsa97de3f926ac
addedAxis-parallel cuboids need unbounded colors97bf4eabc0a8
addedBar-Natan's equivalent statement1f322bb8f52c
addedMap of Europe not four-colorable with water coloredd6f4918f2c